package com.jadesoft.stock.rp;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.PrintWriter;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang.StringUtils;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.DispatchAction;

/**
 * 生成图片验证的图片
 * 
 * @author YZT
 */
public class ImageAction extends DispatchAction {
	private final int width = 60;
	private final int height = 20;
	private final int fontHeight = height - 2;
	private final int codeCount = 4;
	private int x = width / (codeCount+1);
	private int step = 5;//字体间距
	private char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
			'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U',
			'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7',
			'8', '9' };
	private int codeY = height - 2;;

	public ActionForward getImage(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		// 定义图像buffer
		BufferedImage buffImg = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = buffImg.createGraphics();

		// 创建一个随机数生成器类
		Random random = new Random();

		// 将图像填充为白色
		g.setColor(Color.WHITE);
		g.fillRect(0, 0, width, height);

		// 创建字体，字体的大小应该根据图片的高度来定。
		Font font = new Font("Fixedsys", Font.PLAIN, fontHeight);
		// 设置字体。
		g.setFont(font);

		// 画边框。
		g.setColor(Color.WHITE);
		g.drawRect(0, 0, width - 1, height - 1);

		// 随机产生60条干扰线，使图象中的认证码不易被其它程序探测到。
		g.setColor(Color.cyan);
		for (int i = 0; i < 10; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}

		// randomCode用于保存随机产生的验证码，以便用户登录后进行验证。
		StringBuffer randomCode = new StringBuffer();
		int red = 0, green = 0, blue = 0;

		// 随机产生codeCount数字的验证码。
		for (int i = 0; i < codeCount; i++) {
			// 得到随机产生的验证码数字。
			String strRand = String.valueOf(codeSequence[random.nextInt(36)]);
			// 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。
			red = random.nextInt(255);
			green = random.nextInt(255);
			blue = random.nextInt(255);
			// 用随机产生的颜色将验证码绘制到图像中。
			g.setColor(new Color(red, green, blue));
			g.drawString(strRand, i  * x+step, codeY);

			// 将产生的四个随机数组合在一起。
			randomCode.append(strRand);
		}
		// 将四位数字的验证码保存到Session中。
		HttpSession session = request.getSession();
		session.setAttribute("validateCode", randomCode.toString());

		// 禁止图像缓存。
		response.setHeader("Pragma", "no-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);

		response.setContentType("image/jpeg");

		// 将图像返回到浏览器
		ServletOutputStream sos = response.getOutputStream();
		ImageIO.write(buffImg, "jpeg", sos);
		sos.close();
		return null;
	}

	/**
	 * 验证图片输入
	 */
	public ActionForward validate(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		response.setContentType("text/html;charset=utf-8");
		String validateC = (String) request.getSession().getAttribute(
				"validateCode");
		String veryCode = request.getParameter("code");
		PrintWriter out = response.getWriter();
		veryCode = veryCode.toUpperCase();
		out.println(validateC.equals(veryCode));
		out.flush();
		out.close();
		return null;
	}

}
